1. Field of the Invention
The present invention relates to spindle motors for use with storage disc drives and, more particularly, to a spindle motor for a disc drive that utilizes the electrical connector as the solitary means of sealing the internal motor bearing structure from the surrounding environment.
2. Description of Related Art
One requirement for the proper operation of a disc drive is that the environment inside the head-disc enclosure (HDA) be substantially cleaner then the typical environment outside of the HDA. Foreign particles, greases, and other airborne chemical compounds can attach themselves to the recording head(s) and disc(s). The presence of these substances will disrupt the air bearing generated between the recording heads and the adjacent recording media and could cause head-disc xe2x80x9ccrashesxe2x80x9d resulting in permanent loss of data. It is equally important to seal potential flow paths through the spindle bearings where xe2x80x9coutsidexe2x80x9d air can flow into the HDA. Air cycling through this path can carry grease particles and surfactants from the bearing grease, which are detrimental to the head disc interface for the reasons mentioned above. Such airflow can also act to deplete moisture from the bearing grease, thus reducing its lubricating efficiency and shortening bearing life. To resolve this problem, it is common in current disc drive architecture to provide a bearing cap or ferro-fluidic seal to prevent flow through the ball bearing structure and into the HDA. It is also common to provide a means for sealing airflow that can occur around the electrical motor connections. In the past, this has been done with tight tolerance labyrinth structures or the addition of a thin metal piece referred to as a xe2x80x9cbearing cap. xe2x80x9d Both of these methods of sealing the HDA have proven to be expensive, time consuming, and process sensitive.
The cost associated with the addition of a bearing cap, ferro-fluidic seal or any other such method outlined above is not only limited to the cost of the part itself. There is an additional cost associated with the process of attaching the cap, ferro-fluidic seal, etc., to the motor, (typically, an adhesive is used). Adhesive-curing time acts to limit production throughput increasing manufacturing costs.
U.S. Pat. No. 5,274,288 to Frederick Mark Stefansky entitled xe2x80x9cLow Noise Spin Motor For Use In Disc Drive,xe2x80x9d issued December 28, 1993, discloses a header 36 which interconnects actuator interface circuitry 38 with the control circuitry on printed circuit wiring board 14. The interface circuitry 38 is interconnected with the voice coil motor of actuator 28 through flexible ribbon cable 40. U.S. Pat. No. 5,621,582 to Frederick Mark Stefansky, entitled xe2x80x9cDisc Drive Including A Base Plate Well For The Spin Motor,xe2x80x9d issued Apr. 15, 1997, discloses a single electrical contractor (header) that transfers all electrical signals between the exterior and the interior of the casing, thereby reducing the possibility of the introduction of contaminants to the controlled environment within the casing. Both of these patents are assigned to the same assignee as the present application, and are herein incorporated by reference for the information relating to the invention described in this application.
The present invention relates to a spindle motor including a motor housing where said motor housing has a single opening, the opening containing a connector molded to fit snugly into said single opening with the connector including a hole through which the motor drive wires pass. The connector further includes a first section and a raised portion on the first section with said raised portion having a plurality of conducting electrical contact members molded into said raised portion to which the external ends of the motor drive wires are connected. Further, the connector further comprises an annular ring on the side opposite from said raised portion of the molded connector with the annular ring being used to contact a complementary receiving area of the motor housing to cause a tight fit for said molded connector to said motor bearing. The second embodiment includes a molded electrical connector comprising a first section which is generally circularly shaped, a raised portion on one side of the first section, electrical contact members formed in said raised portion, a hole placed in said first portion, and including an annular ring on the second side of such a first section. This embodiment further includes a motor housing upon which the connectors are mounted and includes conducting wires from said motor housing passing through said holes to provide an electrical path for drive signals to said motor. The invention in this embodiment also includes an adhesive which is placed in the hole and around the wires to completely seal the hole and wires.